add this example to Java world and fixing bugs

scala-package/.gitignore

@@ -9,3 +9,4 @@ core/src/main/scala/org/apache/mxnet/SymbolBase.scala
 core/src/main/scala/org/apache/mxnet/SymbolRandomAPIBase.scala
 examples/scripts/infer/images/
 examples/scripts/infer/models/
+examples/scripts/infer/objectdetector/boundingImage.png

scala-package/examples/src/main/java/org/apache/mxnetexamples/javaapi/infer/objectdetector/README.md

@@ -84,7 +84,7 @@ After the previous steps, you should be able to run the code using the following
 From the `scala-package/examples/scripts/infer/objectdetector/` folder run:
 
 ```bash
-./run_ssd_example.sh ../models/resnet50_ssd/resnet50_ssd_model ../images/dog.jpg ../images
+./run_ssd_java_example.sh ../models/resnet50_ssd/resnet50_ssd_model ../images/dog.jpg ../images
 ```
 
 **Notes**:

scala-package/examples/src/main/java/org/apache/mxnetexamples/javaapi/infer/objectdetector/SSDClassifierExample.java

@@ -28,12 +28,11 @@
 import org.apache.mxnet.infer.javaapi.ObjectDetector;
 
 // scalastyle:off
+import javax.imageio.ImageIO;
 import java.awt.image.BufferedImage;
 // scalastyle:on
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
+import java.util.*;
 
 import java.io.File;
 
@@ -128,22 +127,34 @@ public static void main(String[] args) {
         try {
             Shape inputShape = new Shape(new int[]{1, 3, 512, 512});
             Shape outputShape = new Shape(new int[]{1, 6132, 6});
-
-
-            int width = inputShape.get(2);
-            int height = inputShape.get(3);
+
             StringBuilder outputStr = new StringBuilder().append("\n");
 
             List<List<ObjectDetectorOutput>> output
                     = runObjectDetectionSingle(mdprefixDir, imgPath, context);
-
+
+            // Creating Bounding box material
+            BufferedImage buf = ImageIO.read(new File(imgPath));
+            int width = buf.getWidth();
+            int height = buf.getHeight();
+            List<Map<String, Integer>> boxes = new ArrayList<>();
+            List<String> names = new ArrayList<>();
             for (List<ObjectDetectorOutput> ele : output) {
                 for (ObjectDetectorOutput i : ele) {
                     outputStr.append("Class: " + i.getClassName() + "\n");
                     outputStr.append("Probabilties: " + i.getProbability() + "\n");
-
-                    List<Float> coord = Arrays.asList(i.getXMin() * width,
-                            i.getXMax() * height, i.getYMin() * width, i.getYMax() * height);
+                    names.add(i.getClassName());
+                    Map<String, Integer> map = new HashMap<>();
+                    float xmin = i.getXMin() * width;
+                    float xmax = i.getXMax() * width;
+                    float ymin = i.getYMin() * height;
+                    float ymax = i.getYMax() * height;
+                    List<Float> coord = Arrays.asList(xmin, xmax, ymin, ymax);
+                    map.put("xmin", (int) xmin);
+                    map.put("xmax", (int) xmax);
+                    map.put("ymin", (int) ymin);
+                    map.put("ymax", (int) ymax);
+                    boxes.add(map);
                     StringBuilder sb = new StringBuilder();
                     for (float c : coord) {
                         sb.append(", ").append(c);
@@ -152,7 +163,12 @@ public static void main(String[] args) {
                 }
             }
             logger.info(outputStr.toString());
-
+
+            // Covert to image
+            Image.drawBoundingBox(buf, boxes, names);
+            File outputFile = new File("boundingImage.png");
+            ImageIO.write(buf, "png", outputFile);
+
             List<List<List<ObjectDetectorOutput>>> outputList =
                     runObjectDetectionBatch(mdprefixDir, imgDir, context);
 
@@ -177,7 +193,6 @@ public static void main(String[] args) {
                 }
             }
             logger.info(outputStr.toString());
-
         } catch (Exception e) {
             logger.error(e.getMessage(), e);
             parser.printUsage(System.err);

scala-package/infer/src/main/scala/org/apache/mxnet/infer/ObjectDetector.scala

@@ -132,7 +132,7 @@ class ObjectDetector(modelPathPrefix: String,
     if (topK.isDefined) {
       var sortedIndices = predictResult.zipWithIndex.sortBy(-_._1(1)).map(_._2)
       sortedIndices = sortedIndices.take(topK.get)
-      // takeRight(5) would provide the output as Array[Accuracy, Xmin, Ymin, Xmax, Ymax
+      // takeRight(5) would provide the output as Array[Accuracy, Xmin, Ymin, Xmax, Ymax]
       result = sortedIndices.map(idx
       => (synset(predictResult(idx)(0).toInt),
           predictResult(idx).takeRight(5))).toIndexedSeq

scala-package/infer/src/main/scala/org/apache/mxnet/infer/javaapi/ObjectDetectorOutput.scala

@@ -52,14 +52,14 @@ class ObjectDetectorOutput (className: String, args: Array[Float]){
     *
     * @return       Float of the max X coordinate for the object bounding box
     */
-  def getXMax: Float = args(2)
+  def getXMax: Float = args(3)
 
   /**
     * Gets the minimum Y coordinate for the bounding box containing the predicted object.
     *
     * @return       Float of the min Y coordinate for the object bounding box
     */
-  def getYMin: Float = args(3)
+  def getYMin: Float = args(2)
 
   /**
     * Gets the maximum Y coordinate for the bounding box containing the predicted object.

scala-package/infer/src/test/java/org/apache/mxnet/infer/javaapi/ObjectDetectorOutputTest.java

@@ -36,8 +36,8 @@ public void testConstructor() {
         Assert.assertEquals(odOutput.getClassName(), predictedClassName);
         Assert.assertEquals("Threshold not matching", odOutput.getProbability(), 0f, delta);
         Assert.assertEquals("Threshold not matching", odOutput.getXMin(), 1f, delta);
-        Assert.assertEquals("Threshold not matching", odOutput.getXMax(), 2f, delta);
-        Assert.assertEquals("Threshold not matching", odOutput.getYMin(), 3f, delta);
+        Assert.assertEquals("Threshold not matching", odOutput.getXMax(), 3f, delta);
+        Assert.assertEquals("Threshold not matching", odOutput.getYMin(), 2f, delta);
         Assert.assertEquals("Threshold not matching", odOutput.getYMax(), 4f, delta);
 
     }